- Highest quality exhaust valves manufactured by G & S Valves.
- Following Head Sizes available (check your original) : 1.735" or 1.750" (please state which head size when ordering).
- standard Model 30\40 stem diameter : 3/8"
- Stem length: 4.650", these valves already have the collet groove machined and are ready to fit. Note: Norton cammy valves were made in a variety of lengths over the years, although not the most common, this length - 4.650" was sometimes used, particularly with larger inlet valve heads. If you have an original then measure that. If you are unsure please email me